[PATCH 3/4] selftests/lkdtm: Reset WARN_ONCE to avoid false negatives

[Kees Cook]

Since we expect to see warnings every time for many tests, just reset
the WARN_ONCE flags each time the script runs.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 tools/testing/selftests/lkdtm/run.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
index ee64ff8df8f4..8383eb89d88a 100755
--- a/tools/testing/selftests/lkdtm/run.sh
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -8,6 +8,7 @@
 #
 set -e
 TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT
+CLEAR_ONCE=/sys/kernel/debug/clear_warn_once
 KSELFTEST_SKIP_TEST=4
 
 # Verify we have LKDTM available in the kernel.
@@ -67,6 +68,11 @@ cleanup() {
 }
 trap cleanup EXIT
 
+# Reset WARN_ONCE counters so we trip it each time this runs.
+if [ -w $CLEAR_ONCE ] ; then
+	echo 1 > $CLEAR_ONCE
+fi
+
 # Save existing dmesg so we can detect new content below
 dmesg > "$DMESG"
 
-- 
2.25.1